Hot zone arrangement for a vacuum furnace

Abstract

The present arrangement is a hot zone structure for a vacuum furnace which includes an endlessly shaped outside wall (e.g. shaped substantially into a circle) preferably made of stainless steel. Disposed next to the inside surface of the outside wall is a layer or layers of heat insulating material means such as graphite felt. Further disposed next to the inside surface of the insulating material means is an inside wall preferably made of graphite. The inside wall defines the chamber of the hot zone structure into which items to be heat treated are placed. Passing through the outside wall, through the layer of heat insulating material, and through the inside wall are many continuous apertures. At the end of each continuous aperture there is located a threaded terminal piece and threaded into each terminal piece is a graphite nozzle. Accordingly there is a plurality of graphite nozzles passing from outside the outside wall of the hot zone structure through into the inside chamber of the hot zone structure. Through the graphite nozzles gasses can be passed from outside of the hot zone structure to the inside thereof for quenching purposes. The graphite nozzles are each removable and do not freeze or bind in the terminal pieces as do nozzles made of other materials.

I claim: 
     
       1. A vacuum furnace hot zone comprising in combination: outside wall means having at least one aperture therein; inside wall means having at least one aperture therein and having an inside surface disposed to define the inside chamber of a hot zone of a vacuum furnance; heat insulating material means disposed between said outside wall means and said inside wall means and having at least one aperture therein; said one aperture in said outside wall means disposed to be in alignment with said at least one aperture in said heat insulating material means and said at least one aperture in said heat insulating material means disposed to be in alignment with said at least one aperture in said inside wall means to form a continuous aperture through said outside wall means, said heat insulation material means and said inside wall means; first fastening means disposed at the end of said continuous aperture and secured to said outside wall; and graphite nozzle means disposed in said continuous aperture and securely fastened into said first fastening means for permitting gasses to pass from the outside of said outside wall means through said heat insulating material means and through said inside wall means to the hot zone of a vacuum furnace. 
     
     
       2. A vacuum furnace hot zone according to claim 1 wherein there is further included a second fastening means threaded over said graphite nozzle to come to rest against said inside surface of said inside wall means to further securely fasten said graphite nozzle in a fixed position.